Hi,
that is a vertex count limit and for each entity. The max polycount of a scene depends on materials and machine. I remember been able to render more than 2M polygons with simple materials and less than 50K with depthmaps, normalmaps and multiple views involved. The max polycount of a scene is not really measurable with no defined rendering pipeline. I would say there is no reference by the way.

The LOD system of the engine is a raw lod stage management, inherited from dx I think. No facades and no soft steps merging.

Salud!